Iso-adenosine-3{40 ,5{40 -monophosphoric acid and its salts

ABSTRACT

nnolly and Hutz

United seam mm Theodore Pasternak Geneva, Switzerland;

Georges (Dorde) Cehovlc, Villejull, France; llan Marcus, Geneva, Switzerland; Sathyavathy Vengadabady, Vltry-sur- [72] Inventors [54] lS0-ADENOSlNE-3 ',5'-MONOPHOSPHORIC ACID AND ITS SALTS 4 Claims, No Drawings 52 us. Cl 260311.531, 260/999 [51] Int. Cl C07d 51/54 [50] Field of Search 260/211.5, 211.5 R

[56] References Cited UNITED STATES PATENTS 3,457,253 7/1969 Wechter 160/2l 1 5 3,462,414 8/1969 Wechter 260/2ll5 ABSTRACT: The compound iso-adenosine-3'.5 '-monophosphorlc aeid is provided which has the formula lSO-ADENOSlNE-S ,5 '-MONOPHOSPHORIC ACID AND ITS SALTS .I ll

and its salts.

Similarly to adenosine 3', 5-monophosphoric acid (cyclic AMP), known to act as second intracellular messenger with respect to a large number of hormones, cyclic iso-AMP generates the dispersion of melanophores in the skin of the frog in vitro and the dilatation of melanophores in the skin of the lizard in vitro, and it increases the liberation of the hormone thyretorope (TSH) by hypophysis in rats in vitro, but, in all these tests, it shows itself clearly superior to the base nucleotide (cyclic AMP) which is surprising.

According to a further feature of the invention, the compound cyclic iso-AMP is prepared by transforming (noncyclic) iso-AMP into a p-nitrophenolic ester form, by the action of p-nitrophenol in the presence of dicyclohexyl carbodiimide, and then treating this ester with potassium (tert) butoxide.

The following example illustrates the production of cyclic iso-AMP.

PREPARATION OF lSO-ADENOSlNE-S', 5-PHOSPHORIC AND (CYCLlC ISO-AMP) AND ITS SALTS The iso-adenosine-S-phosphoric acid (iso-AMP) was prepared according to the method of Leonard & Laursen (Biochemistry 4, 354 (1965)).

Fifty mg. of iso-AMP in the form of the free acid, carefully dried, were dissolved in a mixture of 2 ml. pyridine, and 2 ml. dimethyl formamide. There were added 0.104 ml. tri-n-butylamine, 557 mg. p-nitrophenol and 824 mg. of dicyclohexyl carbodiimide. The mixture was stirred in the dark for 48 hours. The nucleotide then passed into solution. By paper chromatography (ethanol/ammonium acetate 0.5 M; 5:2 by volume), three substances were detected: the p-nitrophenolic ester of iso-AMP, the corresponding pyrophosphate and the excess p-nitrophenol. The solution was then evaporated to dryness and the residue taken up in 10 ml. water. After filtration, extraction 5 times was dried out, each time with 10 ml. ether, to remove the. p-nitrophenol and the excess dicyclohexy carbodiimide. The aqueous solution was poured into a column (40 cm. long and 2.8 cm. diameter) of DEAE cellulose in the form of its bicarbonate. The column was washed with 500 ml. of double-distilled water and elution by concentration gradient was carried out by means of water gradually dosed with 0.1 M triethylammonium bicarbonate (pH 7.5) (used to a total of 3 liters of mixture). Fractions of 20 ml. were collected. As indicated by paper chromatography, the p-nitrophenolic ester of iso-AMP is contained in fractions -80. These fractions, remixed together, were evaporated to dryness and coevaporated several times with methanol to eliminate triethylamine. Yield 76-80 percent of the total phosphorus dosage.

A max 256 my; s max 19,600.

The solution is evaporated to dryness. The residue which is the triethylammonium salt of the ester is dried over P 0, under high vacuum: 186 mg. obtained. This was dissolved in 20 ml. anhydrous dimethyl sulfoxide and 2 ml. of a 1 solution of potassium t-butoxide in anhydrous t-butanol were added, which generated the formation of cyclic iso-AMP with the liberation of P-nitrophenate. At the end of 3 hours at normal temperature, 10 times the theoretical quantity of DOWEX (NH, form) dried under vacuum at were added. The mixture was shaken and filtered. The resin was washed with 0.2 M

. ammonia until complete elution of the cyclic nucleotide. The

ammonia was driven off by evaporation under vacuum and fractionation carried out as indicated above in a column of DEAE cellulose. Tubes -100 contained the cyclic nucleotide: their contents were evaporated to dryness under vacuum. The residue was taken up in 0.5 ml. methanol and 2.5 ml. ofa 0.5 M solution of sodium perchlorate in acetone added; the

-precipitation is completed by addition of 5 ml. anhydrous By decomposition, in aqueous solution by means of hydrogen sulfide there is obtained a solution of cyclic iso-AMP in the form of the free acid. This latter is amorphous. By neutralization by means of a mineral or organic base, the corresponding salts are obtained.

The iso-adenosine-3, 5-monophosphoric acid and its salts are useful for biochemical and pharmaceutical research.

What we claim is:

l. The compound iso-adenosine-3, 5'-monophosphoric symmetrical 6O monophosphoric acid of the formula IIIH,

Ii il l which comprises reacting adenosine 3, 5'-monophosphoric 3, A di l f h compnund fclaim 1, acid with p-nitrophenol in the presence of dicyclohexyl car 4 A ilv r alt ofth compound ofclaim l. hodiimide and reacting the product with potassium tert butoxide. 

2. A method for the production of iso-adenosine-3'', 5'' monophosphoric acid of the formula
 3. A sodium salt of the compound of claim
 1. 4. A silver salt of the compound of claim
 1. 